311 lines
12 KiB
Python

from __future__ import print_function
import utils
import copy
import numpy as np
from collections import deque
'''
Settings of the Go game.
(1, 1) is considered as the upper left corner of the board,
(size, 1) is the lower left
'''
NEIGHBOR_OFFSET = [[1, 0], [-1, 0], [0, -1], [0, 1]]
CORNER_OFFSET = [[-1, -1], [-1, 1], [1, 1], [1, -1]]
class Go:
def __init__(self, **kwargs):
self.size = kwargs['size']
self.komi = kwargs['komi']
def _flatten(self, vertex):
x, y = vertex
return (x - 1) * self.size + (y - 1)
def _deflatten(self, idx):
x = idx // self.size + 1
y = idx % self.size + 1
return (x, y)
def _in_board(self, vertex):
x, y = vertex
if x < 1 or x > self.size: return False
if y < 1 or y > self.size: return False
return True
def _neighbor(self, vertex):
x, y = vertex
nei = []
for d in NEIGHBOR_OFFSET:
_x = x + d[0]
_y = y + d[1]
if self._in_board((_x, _y)):
nei.append((_x, _y))
return nei
def _corner(self, vertex):
x, y = vertex
corner = []
for d in CORNER_OFFSET:
_x = x + d[0]
_y = y + d[1]
if self._in_board((_x, _y)):
corner.append((_x, _y))
return corner
def _find_group(self, current_board, vertex):
color = current_board[self._flatten(vertex)]
# print ("color : ", color)
chain = set()
frontier = [vertex]
has_liberty = False
while frontier:
current = frontier.pop()
# print ("current : ", current)
chain.add(current)
for n in self._neighbor(current):
if current_board[self._flatten(n)] == color and not n in chain:
frontier.append(n)
if current_board[self._flatten(n)] == utils.EMPTY:
has_liberty = True
return has_liberty, chain
def _is_suicide(self, current_board, color, vertex):
current_board[self._flatten(vertex)] = color # assume that we already take this move
suicide = False
has_liberty, group = self._find_group(current_board, vertex)
if not has_liberty:
suicide = True # no liberty, suicide
for n in self._neighbor(vertex):
if current_board[self._flatten(n)] == utils.another_color(color):
opponent_liberty, group = self._find_group(current_board, n)
if not opponent_liberty:
suicide = False # this move is able to take opponent's stone, not suicide
current_board[self._flatten(vertex)] = utils.EMPTY # undo this move
return suicide
def _process_board(self, current_board, color, vertex):
nei = self._neighbor(vertex)
for n in nei:
if current_board[self._flatten(n)] == utils.another_color(color):
has_liberty, group = self._find_group(current_board, n)
if not has_liberty:
for b in group:
current_board[self._flatten(b)] = utils.EMPTY
def _check_global_isomorphous(self, history_boards, current_board, color, vertex):
repeat = False
next_board = copy.copy(current_board)
next_board[self._flatten(vertex)] = color
self._process_board(next_board, color, vertex)
if next_board in history_boards:
repeat = True
return repeat
def _is_eye(self, current_board, color, vertex):
nei = self._neighbor(vertex)
cor = self._corner(vertex)
ncolor = {color == current_board[self._flatten(n)] for n in nei}
if False in ncolor:
# print "not all neighbors are in same color with us"
return False
_, group = self._find_group(current_board, nei[0])
if set(nei) < group:
# print "all neighbors are in same group and same color with us"
return True
else:
opponent_number = [current_board[self._flatten(c)] for c in cor].count(-color)
opponent_propotion = float(opponent_number) / float(len(cor))
if opponent_propotion < 0.5:
# print "few opponents, real eye"
return True
else:
# print "many opponents, fake eye"
return False
def _knowledge_prunning(self, current_board, color, vertex):
# forbid some stupid selfplay using human knowledge
if self._is_eye(current_board, color, vertex):
return False
# forbid position on its own eye.
return True
def _is_game_finished(self, current_board, color):
'''
for each empty position, if it has both BLACK and WHITE neighbors, the game is still not finished
:return: return the game is finished
'''
board = copy.deepcopy(current_board)
empty_idx = [i for i, x in enumerate(board) if x == utils.EMPTY] # find all empty idx
for idx in empty_idx:
neighbor_idx = self._neighbor(self.deflatten(idx))
if len(neighbor_idx) > 1:
first_idx = neighbor_idx[0]
for other_idx in neighbor_idx[1:]:
if board[self.flatten(other_idx)] != board[self.flatten(first_idx)]:
return False
return True
def _action2vertex(self, action):
if action == self.size ** 2:
vertex = (0, 0)
else:
vertex = self._deflatten(action)
return vertex
def _is_valid(self, history_boards, current_board, color, vertex):
### in board
if not self._in_board(vertex):
return False
### already have stone
if not current_board[self._flatten(vertex)] == utils.EMPTY:
return False
### check if it is suicide
if self._is_suicide(current_board, color, vertex):
return False
### forbid global isomorphous
if self._check_global_isomorphous(history_boards, current_board, color, vertex):
return False
return True
def simulate_is_valid(self, state, action):
history_boards, color = state
vertex = self._action2vertex(action)
current_board = history_boards[-1]
if not self._is_valid(history_boards, current_board, color, vertex):
return False
if not self._knowledge_prunning(current_board, color, vertex):
return False
return True
def simulate_is_valid_list(self, state, action_set):
# find all the invalid actions
invalid_action_list = []
for action_candidate in action_set[:-1]:
# go through all the actions excluding pass
if not self.simulate_is_valid(state, action_candidate):
invalid_action_list.append(action_candidate)
if len(invalid_action_list) < len(action_set) - 1:
invalid_action_list.append(action_set[-1])
# forbid pass, if we have other choices
# TODO: In fact we should not do this. In some extreme cases, we should permit pass.
return invalid_action_list
def _do_move(self, board, color, vertex):
if vertex == utils.PASS:
return board
else:
id_ = self._flatten(vertex)
board[id_] = color
return board
def simulate_step_forward(self, state, action):
# initialize the simulate_board from state
history_boards, color = state
vertex = self._action2vertex(action)
new_board = self._do_move(copy.copy(history_boards[-1]), color, vertex)
history_boards.append(new_board)
new_color = -color
return [history_boards, new_color], 0
def executor_do_move(self, history, latest_boards, current_board, color, vertex):
if not self._is_valid(history, current_board, color, vertex):
return False
current_board[self._flatten(vertex)] = color
self._process_board(current_board, color, vertex)
history.append(copy.copy(current_board))
latest_boards.append(copy.copy(current_board))
return True
def _find_empty(self, current_board):
idx = [i for i,x in enumerate(current_board) if x == utils.EMPTY ][0]
return self._deflatten(idx)
def _find_boarder(self, current_board, vertex):
_, group = self._find_group(current_board, vertex)
border = []
for b in group:
for n in self._neighbor(b):
if not (n in group):
border.append(n)
return border
def _add_nearby_stones(self, neighbor_vertex_set, start_vertex_x, start_vertex_y, x_diff, y_diff, num_step):
'''
add the nearby stones around the input vertex
:param neighbor_vertex_set: input list
:param start_vertex_x: x axis of the input vertex
:param start_vertex_y: y axis of the input vertex
:param x_diff: add x axis
:param y_diff: add y axis
:param num_step: number of steps to be added
:return:
'''
for step in xrange(num_step):
new_neighbor_vertex = (start_vertex_x, start_vertex_y)
if self._in_board(new_neighbor_vertex):
neighbor_vertex_set.append((start_vertex_x, start_vertex_y))
start_vertex_x += x_diff
start_vertex_y += y_diff
def _predict_from_nearby(self, current_board, vertex, neighbor_step=3):
'''
step: the nearby 3 steps is considered
:vertex: position to be estimated
:neighbor_step: how many steps nearby
:return: the nearby positions of the input position
currently the nearby 3*3 grid is returned, altogether 4*8 points involved
'''
for step in range(1, neighbor_step + 1): # check the stones within the steps in range
neighbor_vertex_set = []
self._add_nearby_stones(neighbor_vertex_set, vertex[0] - step, vertex[1], 1, 1, neighbor_step)
self._add_nearby_stones(neighbor_vertex_set, vertex[0], vertex[1] + step, 1, -1, neighbor_step)
self._add_nearby_stones(neighbor_vertex_set, vertex[0] + step, vertex[1], -1, -1, neighbor_step)
self._add_nearby_stones(neighbor_vertex_set, vertex[0], vertex[1] - step, -1, 1, neighbor_step)
color_estimate = 0
for neighbor_vertex in neighbor_vertex_set:
color_estimate += current_board[self._flatten(neighbor_vertex)]
if color_estimate > 0:
return utils.BLACK
elif color_estimate < 0:
return utils.WHITE
def executor_get_score(self, current_board, is_unknown_estimation=False):
'''
is_unknown_estimation: whether use nearby stone to predict the unknown
return score from BLACK perspective.
'''
_board = copy.deepcopy(current_board)
while utils.EMPTY in _board:
vertex = self._find_empty(_board)
boarder = self._find_boarder(_board, vertex)
boarder_color = set(map(lambda v: _board[self._flatten(v)], boarder))
if boarder_color == {utils.BLACK}:
_board[self._flatten(vertex)] = utils.BLACK
elif boarder_color == {utils.WHITE}:
_board[self._flatten(vertex)] = utils.WHITE
elif is_unknown_estimation:
_board[self._flatten(vertex)] = self._predict_from_nearby(_board, vertex)
else:
_board[self._flatten(vertex)] =utils.UNKNOWN
score = 0
for i in _board:
if i == utils.BLACK:
score += 1
elif i == utils.WHITE:
score -= 1
score -= self.komi
return score